Multiplex telegraph system



March 14, 1933. H. H. HAGLUND MULTIPLEX TELEGRAPH SYSTEM Original Filed Feb. 27, 1929 '7 Sheets-Sheet AMP; lF/ER Film fl s/e/m L5 @W m/M dttorncg March 14, 1933. H. HAGLUND 1,901,296

MULTIPLEX TELEGRAPH SYSTEM Original Filed Feb. 27, 1929 7 Sheets-Sheet 2 I -+|'l+a 1 AMPL/F/ER C3 BR! 'P/cx UP RINGS +1 1 L? Q i! Q Q B U a PRINTER 801.10 RING 3 J r IF air v1. PRINTER some RING 35 K .3 PJVVV +EI 47 655/45 715 6 Jnvcntor 152/1 Maj/H2762 W g P W-M.

Gnorucg March 14, 1933. H, H, HAGLUND MULTIPLEX TELEGRAPH SYSTEM Original Filed Feb. 27. 1929 7 Sheets-Sheet 5 F EWING? x uhm rwsw P/6K up FfM/G S WITH W Bummer Hilfflafy/and (510155 /LD r mrcnicu March 14, 1933. H, H. HAGLUND MULTIPLEX TELEGRAPH SYSTEM Original Filed Feb. 27, 1929 7 Sheets-Sheet 4 LINE RINGS QDQDQBUUQUUUH TRANSFORMER March 14, 1933. H. H. HAGLUND 1,901,296

MULTIPLEX TELEGRAPH SYSTEM Original Filed Feb. 27, 1929 7 SheetsSheet 5 6. fa'n Linc,

SEND/N6 RING 2 1cm 4/)? RINGS STORING I a 3 fiuggugu iugluglumuguglug i IHJUJHI IE I IFTTINJTJW WEST SEND/N6 RING RFI-RANs/ ITT/NG PIA/ Envcntor Littomcg March 14, 1933. H. H. HAGLUND 1,901,296

MULTIPLEX TELEGRAPH SYSTEM Original Filed Feb. 27, 1929 7 Sheets-Sheet 6 9 W 5' q a q' ORRE TOFP PICK UP RIN PRINTER PICK U R/NG [P PICK up $01.10 R/Ns MMF 22%;

26 RfCE/V/NG RINGS PRINTER MAGNET-Q 3 mentor Gum-neg 'tion is to overcome the above difiiculties met- Patented Mar. 14, 1933 UNITED STATES PATENT! OFFICE HAKON H. HAGLUND,'OF FLUSHING, NEW YORK, ASSIGNOB, TO THE WESTERN UNION TELEGRAPH COMPANY, OF NEW YORK, N. Y A CORPORATION OF NEW YORK lllfl'l'IL'lIPLEX TELEGRAPH SYSTEM Application filed February 27, 1929, Serial No. 343,109. Renewed October 14, 1931.

This invention relates to telegraph systems i and more particularly to a system for receivfore constructed, to employ electro-magnetic relays connected directly to the line or through a signal amplifier, to respondto the received signal impulses. Appreciable time is required, however, to magnetize and demagnetize the magnets of such rela s and sion'oii signals over the line or cable. They the'relay tongues have considerable inertia,

which limit the rate of operation thereof.

Consequently such'relays are relatively slow in operation and limit the rate, of transmisalso increase the inductance of the line, causing distortion of thersignals. In cable telegyhighl sensitive in order to follow the sig;

' raphy where the signals are highly attenuated and the received impulses build up slowly in amplitude, the relays must be 1 m1 cfanges. Such relays are delicate and leisure careful. adjustment and maintenance. ne of the objects of the present inven- 0% high speed or extreme attenuation may be accurately received "and recorded or repeated.

' Another object is to provide receiving apparatus for such a system which will have a distortion ordlnarilyca-used by the magnet jizing' and tie-magnetizing efiects on electro- ,netic relay,

a type in which the discharge is started by long life, which rugged and reliable and whlclrrequlres' a minimum of maintenance and ad'ustment.

Anot er. object is'to eliminate the signal magnetic relays.

- Another object is to produce fast-er operation of the receiving apparatus in response to the received signals, whereby high speed signalling may be practiced. p

A further object is to permit the use of substantially inertialess relays having no moving parts.

Still further objects are to obtain full regeneration of the received signal impulses, or to prolong the same sufliciently to operate relatively slow acting devices from high speed signals and to provide a simple and reliable means of maintaining synchronism between the multiplex apparatus and the received signals.

' Still another object of this invention is to devise a system for operating printers or storing relays directly from the out ut of an amplifier without the interventlon of electro-mechanical relays.

For this purpose I employ a special inertialess electric discharge device which maybe in the form of a gas-filled thermionic tube, interposed between the amplifier and the printer or storing relay.

The invention is illustrated in panying' drawings in which Figure 1 shows the invention as applied to a multiplex printer.-

. Figure 2 illustrates the invention as ap plied to a multiplex printer system for fill ing in sin le element pulses which have been attenuate Figure 3 illustrates the invention as applied to .a land line arranged forduplex operation.

Figure 4 is a modification of the arrangement shown in Fig. 3.

Figure 5 illustrates the invention as applied to a full regenerative repeater using only two storing relays.

the accom- 1 Figure 6 illustrates the invention as ap-. plied to a system for correcting-a rotary distributor.

Figure 7 shows a complete system embod ing the features of Figures 2, 3, 5

In accordance with the present invention I employ in place of the usual electro-magan electrical discharge tube 0 a momentary application of a signal condition thereto, the discharge continuing independently of the applied a al condition until interrupted by a low y controlled means. In one form the electrical dischar e tube may comprise a gas discharge pat which is electro-statically controlled.

A convenient form of discharge tube for this apparatus may comprise a gas-filled thermionic tube of such construction that when the anode is connected to positive battery and a certain potential is applied to the rid, the tube will start" and current will ow from the'anode to the cathode. As soon as the plate current begins to flow the grid is instantly surrounded by a sheath of positive ions and has no further efiect in controlling the plate circuit. This sheath, usually only a fraction of a millimeter thick, contains the whole voltage drop between the grid and the space surrounding it. Changing the grid voltage merely changes the thickness of the sheath and has no effect on the potential of the rest of the space. Hence removal of the grid potential will not stop the plate current, once it is started. However, it can readily be stopped by removing the plate voltage.

The function of the grid may therefore be likened to a trigger. The amount of power required to start the tube is exceedingly small. 1

An electrostatically controlled discharge tube inherently capable of operation in this matter is shown in re-issue patent to Von Lieben and Reisz, No. 13,779, re-issued July 21st, 1914 and entitled Relay for undilatory currents. This tube is more fully described in Elektrotechnische Zcitschrift of November 27th, 1913, pages 1359 to 63. In operating the tube shown by Von Lieben as a trigger device, it is not necessary to observe the exacting conditions described by Von Lieben for obtaining modulation, that is for preventing the discharge from arcing through the grid. Where mercury is employed, the mercury maybe placed directly in the tube where it will be under the direct heating effect of the cathode, since the mercury temperature for the" well defined tri ger action should be above that correspon ing to approximately 40 degrees C.

Another form of thermionic tube having the characteristics describedis disclosed in patent to Irving Langmuir No..1,289,823. The name thyratron has been applied to tubes of this general type in an article entitled Gas-filled thermionic tubes by A. W. Hull, published in the o'urnal of the American Institute of Electrical Engineers, November 1928, page 802, in which other forms are described and in which the characteristics of the Von Lieben tube when employed as a trigger device, are more fully set forth.

The magnitude of the discharge current is independent of the charge applied to the grid as long as the applied potential is sufficient to start the discharge. This starting potential may be positive or even negative,

depending upon the geometry of the tube, particularly the mesh of the grid and the spacing of the grid and plate, but in any case is definite for a particular tube. \Vhere the tube is designated to start upon the application of a zero or negative potential of the control electrode, it is necessary to provide a negative bias to the grid to maintain the tube in a normally inoperated condition, otherwise the tube will be self-starting.

In the embodiment shown hereinafter the signal conditions, either directly or through an amplifier, are applied to the electrical dis charge tube by a circuit interrupter operating in substantial svnchronism with the received signals, whereby a small and reliable part onl of each signal impulse is applied to the discharge tube and simultaneously therewith the output circuit is completed through a second distributor or make and break device. The output circuit may be maintained in a closed condition for any desired period so as to prolong the effective length of the impulses. In case a single tube is employed, the output circuit should be interrupted, of course, in time to interrupt the discharge before the succeeding signal is applied to the tube, but where two or more tubes are used, operating in succession. each discharge may be continued over a period in excess of the time required for the transmission of a single impulse.

While a preferred manner is shown for controlling the starting of the discharge through tubes of this general nature, in response to telegraph signals, it is to be understood, of course, that I do not desire to be limited to the particular means shown.

Referring to Fig. 1 the output circuit of amplifier A is connected on one side to the solid ring' 1 of the pick-up rings of the rotary distributor or circuit interrupter, and on the other side to the filament F of the mionic tube 2. The segments of the segmented pick-up ring of the distributor are connected together and to the grid G of tube 2. The plate element P of the tube is con-- nected to the solid ring 3 of the printer rings. The active segments 8 of the segmented printer ring are connected respectively to the selectingmagnets of the printer, the latter being connected to one pole of the battery 4, the opposite pole being connected to the filament or cathode of the thermionic tube. The brushes .5 and 6 of the rotary distributor are moved over the rings in synchronism with theincoming signal impulses in the usual manner by a synchronous motor, not shown. A small stabilizing battery G may be connected as indicated in dotted lines to keep the grid normally negative with respect to the filament.

The operation of the arrangement shown in Fig. 1 will be readily understood. The incoming signals received by the amplifier are amplified and impressed upon the output circuit which includes the printer pick-up rings and the filament-to-grid path of the thermionic tube 2. At the same instant that the pick-up brush 5 makes contact with a. pick-up segment 9, the printer riu brush 6, connects the positive pole, of gattery 4 through a segment 8 to the plate of tube 21 \Vhen the brush 5 contacts with a pick-up segment 9 it completes the output circuit of amplifier A to the grid circuit of tube 2. If the output of the amplifier is positive, the grid of the tube will be made positive, thereby starting the flow of current from plus battery 4 through a printer selecting magnet, a se ment 8, brush 6, solid ring 3, to the plate P of tube 2, and through the tube to the cathode F and negative pole of battery 4. This will operate the printer selecting magnet. The current will continue to flow until the brush 6 passes onto a dead segment 7, thereby opening the plate circuit.

If theoutput of the amplifier is negative when the pick-up brush passes over the pickup segment, the grid of the thermionic tube will become. more negative and hence no current will be permitted to flow through the tube, even though the printer ring brush 6 connects plus battery to the plate in the same manner as before.

It will thus be seen that the printer magnets will be operated whenever the output of the amplifier is positive but will not be operated when the amplifier output is negative.

For purposes of illustration I have shown the transmitting rings of the distributor connected to the selecting magnets of a printer or recorder but it is obvious that one or more storing relays may be substituted and used to repeat the signals into another line or cable. The segments 8 serve the double purpose of distributing the discharge current to the proper circuit and timing the period of operation of the tube.

Fig. 2 illustrates an arrangement for filling in single element pulses that have been attenuated to such an extent that they Will not operate a relay or a thermionic tube in the normal manner. Two thermionic tubes 2a and 2b of the type described are used, and they are so arranged that they will be operated by alternate incoming signal impulses. Alternate segments of the segmented pick-up ring of the rotary distribu tor are connected to the grid of tube 20, while the remaining segments are connected to the grid of tube 2b. The output circuit of amplifier A is connected on one side through a battery C to solid ring 1 of the pick-up rings, and on the other side to the cathodes of tubes 2a and 2b through a resistance R. The printer rings of the distributor comprise two solid rings and two segmented rings, as

shown. Solid ring 3a is connected to segmented ring 8a by a rotating brush BB while solid ring 3b and segmented ring 8?) are connected together by a rotating brush BB All of the rotating brushes are operated in synchronism with the incoming signal impulses in the usual manner. Plate battery 4 is connected to supply plate current to tubes 2a and 21) through resistance R, and through the printer selecting magnets. Small stabilizing batteries C 0 may be connected between the filament and grid of tubes 2a and 2b, respectively, in series with suitable limiting resistances as indicated in dotted lines. These batteries are poled to maintain the grids negative with respect to the filaments when the grid circuits are open. Battery C is poled in such manner that when connected in the grid circuit of either tube its effect is to overcome the effect of battery C or C and cause the grid to become positive.

The operation of the arrangement shown in Fig. 2 is as follows:

If at the moment the pick-up brushes BR pass over a pick-up segment, the output of the amplifier A is positive, a positive potential will be impressed upon the grid of the thermionic tube which will start the flow of current from the positive pole of battery 4 through the corresponding printer magnet, and its segment, the plate of the thermionic tube to the cathode, and through resistance R to the negative pole of the bat-" tery. This will operate the printer selecting magnet. If, on the other hand, the output of the amplifier is negative when the pick-up brush BR passes over a pick-up segment, the grid of the tube will be made more negative and hence no current will flow through the plate circuit and therefore the corresponding selecting magnet of the print er will not be operated.

If the output of the amplifier is zcro at the moment that the pick-up brush BR, passes over a pick-up segment connected say to thermionic tube 2, the potential from the battery C,- will over-ride the potential frombattery C, thus making the grid positive and hence starting a. flow of currentthrough tube 2*. When the pick-up brush BR, passes over the next segment, which is connected to thermionic tube 2, the tendency of battery C is to over-ride battery C as before, but since at this moment because of the overlapping arrangement bf the A and B segments, current is still flowing through brush BB and tube 2, and through resistance R, and the resulting drop of the potential across this resistance, lowers the potential of the grid to such an extent that it cannot be overcome by the positive potential impressed by the battery C and hence no current will flow through the plate circuit of tube 2. This alternating operation of tubes A and B continues as long as the output of the amplifier is zero. In this manner single impulses are filled-in" by the action of the local circuit and C batteries of the thermionic tubes.

In Fig. 3 is shown a system for operating a printer directly from a duplex land line without the use of an amplifier. The line L is balanced for duplex operation by an artificial line AL. TR represents a transmitting relay or other transmitter. A receiving bridge including elements R1, L 0 and r is connected between line L and artificial line AL in conjugate relation to transmitting relay TR. The grid circuit of ther mionic tube 2 is connected in shunt to resistance R1 and includes the pick-up rings of the telegraph printer. The tube 2 is connected to the printer rings in the. same manner as shown in Fig. 1. C, is a battery which may be employed to stabilize the tube by making the grid negative with respect to the cathode when the grid circuit is open. This battery is connected between the grid and the cathode in series with a suitable limiting resistance.

The operation of Figure 3 is as follows Incoming signals are impressed upon the grid circuit of the tube 2 directly by the potential drop across resistance R. The tube 2 operates to transmit positive impulses only in the same manner as described above in connection with Figure 1.

The arrangement shown in Figure 4 is somewhat like that shown in Figure 3, like elements being indicated by corresponding reference characters. In this figure, however. the grid circuit of tube 2 is connected to the receiving bridge through a transformer T and an additional set of rings C is provided for opening the grid circuit of the tube in synchronism with the operation of the pick-up rings in the primary circuit of the transformer. The arrangement of the elements R1, 0 and L in the receiving bridge is also somewhat different from that shown in Fig. 3.

In F igure 4, the operation, due to the presence of the transformer T, is such that only the front part of the signal is effective in operating tube 2. This is done so that when the signal decays from a negative signal to zero, the change of flux in the transformer which would normally cause a plus potential to be impressed upon the grid of the tube. cannot produce a current in the secondary bc'ausc at this moment. the secondary of the tran former is open through rings C. The operation oi Fig. i will otherwise be understood from a drs riptiou of the operation of Fig. 1. Pmttcry shown in dotted line may be employed for a. abil'r/iiug the grid negative when the grid circuit is open.

The arrangement shown in Fig. 5, a full regenerative repeater system using only two storing relays. EL represents the east line from which signals are received, and \VL represents the "west line to which signals are to be repeated. The thermionic tube 2 is connected to the east line through pick-up rings in the same manner as shown and described in connection with Figure 3. Instead of printer magnets connected to the segments of the rings in the plate circuit of tube 2, alternate segments of the receiving rings are connected to the winding of one storing relay SR, while the remaining segments are connected to the winding of the other storing relay SR Alternate segments of the retransmitting rings of the regenerative repeater are connected to the tongue of one storing relay, and the remaining segments are connected to the tongue of the other storing relay. The solid ring of the retransmitting rings is connected to apex of the west line.

At the same time that the receiving ring brush 6 passes over the segments connected to relay SR, the restoring brush 7 is passing over a segment connected to another coil 81' of the same relay. The current through this coil .97- is maintained at a value which is less than that flowing through brush 6. Hence if the tube 2 has been operated, due to a positive signal being received over the line EL, this current predominates and relay SR is moved to its marking contact. If a. negative signal is received over the line EL, the tube will not be operated, and hence no current will flow through brush 6 to relay SR, and the current supplied through brush 7 to the restoring coil 87", will operate the relay to its spacing contact, thereby causing a spacing impulse to be transmitted into line VVL.

The arrangement shown in Figure 6 illustrates a receiving system embodying a thermionic tube for recording signal impulses received over a. line or cable and which also includes a correcting circuit including a thermionic tube for controlling a correcting device for correcting the phase position of the brushes of the rotary distributor. The input or starting circuit of tube 2 is connected to the incoming line through a resistance R and the printer pick-up ring. The input or starting circuit of tube 20 is also connected to the incoming line through resistance R and a correcting circuit including the brush positioning magnet. The plate circuit of tube 2 includes the printer receiving rings, the printer selecting magnets, battery B, and resistance R. The plate circuit. of tube B includes the corrector magnet (PM. and battery 13.. U, and C are stabilizing batteries for supplying a negative potential to the grids when the grid circuits are open.

The operation of Figure 6 is as follows:

The circuit is so arranged that the printer BB plate and filament of tube 2 receiving elements operate on a plus signal from the line, and the corrector mechanism operates on areversal from minus to plus, if a phase correction of the brushes is necessary. The possibility of operating the corrector at any other point than at the beginning of a plus signal from the line is eliminated by causing a ne ative potential to be laced on the tubes 9. er a positive signal as been picked up by the receiving brushes. The printer pick-up segments normally pick up in the middle of a receiving signal. A plus impulse would operate receiving tube 2, the plate circuit of which is completed through the receiving rings, printer magnets, battery B and resistance R. \Vhen current is still flowing through resistance R and the pick-up brushes move onto a corrector pick-up segment, the drop of potential across the resistance R produces a negative potential at the grid of the tube 20 which is greater than the potential of the line signal and therefore prevents the operation of the corrector tube 20 at the end of a positive impulse. It is evident therefore that the tube 20 can only be operated at the beginning of a positive impulse and at no other time.

It will be observed that the corrector pickup segments are positioned midway between the printer pick-up segments 20. The brushes BR and BB of the rotary distributor are operated in synchronism with the received signal impulses in the well known manner. The brushes are phased so that the brush BR, passes over a segment 20 just as an incoming signal impulse is at full strength in the middle of the signal. It a positive impulse is received at this instant. a positive potential is impressed upon the grid of tube 2 and current will therefore fiow from battery 13,. through the corrcspmiding printer selecting magnet, through brush and through resistance Itback to battery B,. While the current is still flowing in said circuit through tube 2 and the printer magnet. the pick-up brush BR, will contact with the next segment 21 of the corrector pints-up ring and since the positive impulse being rcccived still persists, it will not make the grid of tube 20 positive because the current stili flowing through resistance R produces a drop of potential which assists the battery (I in maintaining the grid of tube 20 suitieiently negative to prevent its operation.

If. however, the brushes are displaced in phase with relation to. the incoming signals. so that the positive signal is received just .15 the brush BB1 engages a correct-or segment 21, thereby causingthe grid of tube 26% to become positive, a current will flow train the corrector battery B2, through correetor magnet CM, pivoted lever 23, contact conductor 26, plate and cathode of tube 20,

conductors 27 and 28 to battery B The magnet CM attracts its armature and causes the dog 29 to move the ratchet 30 the distance of one tooth. The ratchet is connected by a clutch or in some other suitable manner to the shaft carrying the brushes.

In order that the lever 23 and contact 25 shall remain in contact until the magnet GM has caused a complete stroke of the dog 29, the lever 23 is not engaged by a stop on the dog until the armature has nearly completed its stroke, the lever being yieldingly held in either extreme position by a spring jockey 31. This method of correcting the phase position of the brushes by stepping the shaft carrying the brushes either forwardly or backwardly has long been known to telegraph en ineers.

In Figure 7 l have shown a complete receiving system embodying the features disclosed in Figures 2, 3, 5 and 6. The incoming line EL is balanced for duplex operation by the artificial line AL, the receiving bridge which includes the elements R1, L1, 0 and a, being connected between the line EL and the artificial line AL in conjugate relation to the transmitting relay TR. The incoming signals are impressed alternately upon the grid circuits of the tubes 2a and 21) by the pick-up rings 20, as described in con- 9 nection with Figure 2. The cathodes of the tubes 2a and 2b are connected through a. resistance R to the artificial line AL so that the tubes operate by the potential drop occurring across the resistance R1.

2 A biasing battery 03 is connected in series with the solid pick-up ring and is poled so as to apply a bias to the grids of tubes 2a and 2b which will overcome the negative bias applied by batteries C1 and C2. Due to the combined effect of the batteries C1, C2 and C3, and drop in potential across to resistance R, a filling in of signals is obtained when the received signals are attenuated, as described in connection with Figure 2.

The plate circuits of tubes 20: and 2b in clude the solid rings 3a and 3b, brushes BB2 and BB3, segments 8a and 8b, and storing relays SR and SR, respectively. The reiays SR and SR have their contact tongues connected, respectively, to the alternate segments of the retransmitting rings for repeating the signals in re-generated form over the outgoing line FL. The relays are biased to their marking sides by the local restoring rings through the windings 87 and er.

The corrector pick-up rings 21 are connected to the grid of a corrector tube 20 having in its plate circuit the corrector magnet CM, the circuit therefor being tracedL from the plate over conductor 26, contact 25, lever 23, corrector magnet CM, battery B2 and conductors 28 and 27 to the cathode of the tube. The resistance R is connected in the plate circuits of the tubes 2a and 2b and in the grid circuit of the tube 2c, so that the discharge through the corrector tube is blocked whenever a discharge occurs in either of the tubes 2a or 2?). Consequently, the tube 20 will start only when the distributor is out of phase following a spacing signal, as described in connection with Figure 6. The discharge in the tube 20, however, does not effect the starting of a discharge through the other tubes.

It will be noted, therefore, that in the system of Figure 7, the receiver responds to signals received over the duplexed line, alternate signals being distributed to the tubes 2a, and 2b and the resultant discharges in these tubes being prolonged by the elongated segments 8a and 8?) for a period greater than the normal signal period, the signals being retransmitted in regenerated form b the relays SR and SR1 to the outgoing cuplexed line. Attenuated or weak signals are filled in without the use of vibrating relays or similar expedients and the distributors are maintained in synchronism with the incoming signals by the corrector mechanism.

I Wish it to be understood that the illustrative diagrams are merely for the purpose of clearly disclosing my invention and that various changes in the circuits will be obvious to engineers without departing in any manner from the invention.

I claim:

1. In a multiplex telegraph system, the combination of a source of periodic telegraph signals, a distributor equipment including pick-up rings and storage rings, telegraph storage elements connected to said storage rings, a thermionic device of the type described having input and output circuits, said thermionic device being characterized by continued operation unaffected by grid potential after starting, said source of signals and said pick-up rings being included in said input circuit, and said storage rings, said telegraph storage elements and a source of current being included in said outmt circuit.

2. A telegraph system comprising a source of telegraph signals, an amplifier for amplif 'ing said signals, a. thermionic device of the type described including input and out- )llt circuits, said thermionic device being characterized by continued operation unaffected by grid potential after starting, a distributor equipment including solid and segmented rings and a brush movable therewer in synchronism with the received signals, said distributor element bein connected in said input circuit and inclu ed in the output circuit of said amplifier, a second distributor element comprislng transmitting rings and a brush movable thereover in synchronism with said first distributor equipment, signal storage elements connected to the segments of said transmitting distributor, said second distributor element, said signal storage elements and a source of current being included in the output circuit of said thermionic device.

3. A telegraph system comprising a source of telegraph signals, a distributor equipment including transmitting rings and a brush movable t-hereover in synchronism with the received signals, a transmitting circuit connected to the solid and segmented elements of said transmitting rings and including a source of current and a thermionic device characterized by anode, cathode and starting electrode elements so constructed and arranged that current continues to flow in the anode-cathode circuit unaffected by the potential of the starting electrode after being started, and means controlled by the movable member of said distributor for impressing signals from said source upon the starting electrode of said thermionic device synchronously with the signal impulses.

4. A telegraph system comprising a source of telegraph signals, a thermionic device of the type described having input and output circuits, said thermionic device being characterized by continued operation unaffected by grid potential after starting, said source of signals being connected in said input circuit, a distributor ring included in said input circuit, and means for operating said distributor in synchronism with the incoming signals.

5. In a telegraph system the combination of a thermionic device of the type described having input and output circuits, said thermionic device being characterized by continued operation unaffected by grid potential after starting, a source of telegraph signals connected in said input circuit, means included in said input circuit for interrupting said circuit in synchronism with said signals, and means for maintaining the grid of said thermionic device negative with respect to the cathode when said input circuit is open.

6. In a telegraph system, two thermionic devices of the type described including input and output circuits, a distributor equipment including a solid ring, a segmented ring and a rotating brush, alternate segments of said segmented ring being connected to the grid element of one of said devices. and the remaining segments of said segmented ring being connected to the grid element of said second device, a source of telegraph signals connected between the cathodes of said devices and the solid ring of said distributor, distributor elements included in the output circuits of each of said devices, signal responsive devices controlled by each of said last mentioned distributors, and means for rotating the brushes of all said distributors in synchronism with the telegraph signals.

7. In a telegraph system the combination of two thermionic devices of the type described including input and output circuits, a distributor element including a solid ring and a segmented ring alternate elements of which are connected to the grid of one of said devices and the remaining elements connected to the grid of the second device, a source of telegraph signals connected between the cathodes of said devices and the solid ring of said distributor, a source of current connected between the cathode and grid of each device for making the grid negative with respect to the cathode when the grid circuit is open, and a source of current included in a common path of said grid circuits for making the grid positive when the grid circuit is closed by said distributor and the amplitude of the line signal is not sufiicient to determine the grid potential.

8. In a telegraph system the combination of two gaseous thermionic devices of the type described including input and output circuits, a distributor element including a solid ring and a segmented ring alternate elements of which are connected to the grid of one of said devices and the remaining elements connected to the grid of the second device, a source of telegraph signais connected between the cathodes of said devices and the solid ring of said distributor, a source of current connected between the cathode and grid of each device for maintaining the grid negative with respect to the cathode when the grid circuit is open, a source of current included in a common path of said grid circuits for making the grid positive when the grid circuit is closed by said distributor and the amplitude of the line signal is not sufficient to determine the grid potential, and a resistance included in a common. path for the grid circuits and plate circuits of both said devices whereby when )late current flows in one device the grid 0 the other device is maintained negative with respect to its cathode when the grid circuit is completed by said distributor.

9. In a signaling system. a signal responsive means comprising a thermionic tube of the type described wherein the grid, anode and cathode elements are so constructed and arranged that. when started, the current .iowing between anode and cathode is un affected by the grid potential, a source of current, means for connecting said source in circuit with the anode and cathode for predetermined intervals in svnchronism with the signals, and means or impressing a starting voltage upon the grid in synchronism with the signals.

10. The method of repeating signal impulses, which consists in establishing recurrent potentials in synchronismwith the received impulses, causing said potentials to establish a field in an arc path in a circuit connected to a source of power which first starts the How of current from said source across the arc and then automatically nullifies the effect of said field upon the continued flow of current, interrupting the current flow after a predetermined interval and transmitting the recurrent periods of current flow from said source.

11. In a communication system, apparatus for repeating and regenerating the received intelligence signals, comprising a receiving three-element tube relay characterized by the anode, cathode and starting electrode elements so constructed and arranged that current continues to flow in the anodecathode circuit irrespective of the starting electrode potential after being started by a predetermined potential applied to the starting electrode. means for impressing the received signal impulses upon the starting electrode, a source of current and a distributor operating to complete the connection of said source to the anode and cathode and to a transmitting circuit synchronously with the received intelligence signals for predetermined intervals.

12. In a signaling system, receiving means responsive to impulses ofshort duration, electrostatically controlled gas discharge tubes responsive to said short impulses, operating irrespective of grid potential after being started by said impulses, and impulse transmitting means determining the duration of operation of said tubes.

13. In a signaling system, apparatus for receiving from a line or cable impulses of short duration recurring in rapid succession, electromagnetic translating devices, electrostatically controlled gas discharge tubes, having an input circuit including a grid element connected to receive said impulses of short duration and an output circuit including auozic and cathode elements connected to said translating devices, said grid, anode and cathode elements being so constructed and arranged that the output circuit is unaffected by the grid potential after being started, and means for determining the duration of the operation of the output circuit,

14.. In a signaling system, a signal responsive means comprising a thermionic tube of the type described wherein the grid, anode and nthode elements are so constructed and arranged that when started the current flows bet-ween anode and cathode unaffected by the grid potential. a source of current, means for connecting said source in circuit with the anode and cathode for predetet mined intervals in synch ronism with the signals. and means for impressing a starting voltage upon the grid in synchronism with the signals.

15. A communication system. comprising a signal receiving apparatus responsive to intelligence signals of varying polarity including a thermionic tube relay characterized by anode, cathode and starting electrode elements so constructed and arranged that current continues to flow in the anode-cathode circuit unaffected by the potential of the starting electrode after being started by a positive starting potential applied to the starting electrode.

16. In a communication system as set forth in claim 15. means for impressing the received intelligence signals upon the starting electrode. a transmitting circuit including a source of current, and means for connecting said transmitting circuit to the anode and cathode synchronously with the received signals.

17. In a signaling system, an electric discharge device having a controlling circuit and a controlled circuit. an indicating device normally maintained in an unoperated condition. said indicating device being adapted to assume an operative condition by a current in said controlled circuit under the influence of said controlling circuit and to be maintained in said operative condition by said current independent of changes in the condition of the controlling circuit.

18. In a telegraph system, a source of signals. a. gaseous conduction device having a starting condition differing from its operating condition, means for applying a start ing condition to said device in accordance with said signals to initiate a discharge therethrough, and means operating independently of the energy of said discharge for limiting the operating condition, so as to in- Verrupt the discharge.

19. In a telegraph signaling system, a source of signal impulses, a receiver comprising a gaseous conduction device having a starting element, an output circuit for mid device, means for applying a. signal condition to said starting element to initiate a discharge through the device whereby a current flow is produced in the output circuit. means for maintaining said discharge -ndependently of said starting element, current responsive means in said output circuit and means independent of said current responsivc means for interrupting the discharge through said device.

20. In a signaling system, a source of signal impulses. a receiver comprising an elec tric discharge device having a starting ele ment. an output. circuit for said device, means for momentarily applying a signal rendition to the starting element to initiate a discharge through the device whereby current flow is produced in the output circuit. means for maintaining said discharge beyond the period of application of said signal condition to the startingelement, and means independent of said device for interrupting a discharge through the device.

21. In a telegraph signaling system, an electric discharge device, an output circuit therefor, means for applying a signal condition to said device to initiate a discharge therethrough whereby to produce a current flow in said output circuit, means for maintaining said discharge beyond the period of application of said signal condition to the device and means for interrupting said output. circuit externally of the device to terminate the discharge.

22. In a telegraph signaling system, an electric discharge device, means for applying a. signal condition to said device to initiate a discharge theretl'irough, means independent of energy supplied by said signal condition for maintaining the discharge and means operating independently of the energy applied to Dr supplied by said device for terminating the discharge.

23. In a signaling system, an electrostatically controlled gas discharge tube, responsive to short signal impulses, said tube, after a discharge has been started therethrough by a signal impulse, operating irrespective of signal impulses applied thereto and circuit interrupting means for determining the duration of operation of said tube.

24. In a signaling system, an electric discharge device, an output circuit therefor, a source of signals, means for applying said signals to said device to initiate a discharge therethrough and means in said output circuit operating in substantial synchronism with said signals for interrupting the discharge.

25. In a signaling system, an electric discharge device, an output circuit therefor, a source of signals, means for applying said signals to said device to start a discharge therethrough and means in said output circuit operating in definite timed relation to the starting of said discharge for interrupting the discharge.

26. In a signaling system, an electric discharge device, a source of signal impulses, means for applying said impulses to said device to initiate a discharge therethrough. whereby to produce current flow in said output circuit, said device being characterized in that the magnitude ot'the current flow therethrough is constant and independent of the amplitude of the signal impulses, means for maintaining said discharge independent of said signal impulses, and means for ter minating the discharge in timed relation to the signal impulses whereby substantially square-topped signals are produced in said output circuit.

27. In'a communication system, apparatus for receiving telegraph signals, comprising a three-element tube relay characterized by the anode, cathode and starting electrode elements so constructed and arranged that current continues to flow in the anode-cathode circuit irrespective of the starting electrode potential after being started by a predetermined potential applied to the starting electrode, means for impressing the received signal impulses upon the starting electrode, a source of current and means for completing the connection of said source to the anode and cathode synchronously with the received intelligence signals for predetermined intervals.

28. In a signaling system. a signal responsive means comprising an electric discharge device wherein the anode, cathode and starting means are so constructed and arranged that when started the current flows between anode and cathode unaffected by the condition of said starting means, a source of current, means for connecting said source in circuit with the anode and cathode for predetermined intervals in synchronism with the signals, and means for impressing a starting condition upon the starting means in synchronism with the signals.

29. In a communication system, an electric discharge device, means for supplying a signal condition to said device to start a discharge therethrough, means for maintaining said discharge independent of continued application of said signal condition to the device, an output circuit for the device, and a circuit interrupter in said output circuit operating in substantial synchronism with applied signal conditions for terminating the discharge through the device.

30. In a communication system, an electric discharge device, a controlling circuit and a controlled circuit therefor, a source of signals in said controlling circuit, a circuit interrupter in said controlling circuit for determining the application of said signals to the device to time the initiation of a discharge therethrough and a circuit int-errupter in said controlled circuit for timing the termination of said discharge.

31. In a communication system, an electric discharge device, an input circuit therefor, a source of signals, means for applying said signals to the input circuit to initiate a discharge through the device, an output circuit and means operating after the application of a signal impulse to the device for interrupting both the input and output circuits, said input circuit being interrupted prior to the interruption of the output circuit.

32. In a signaling system, an electric discharge device, means for applying telegraph code signal impulses to said device to produce a discharge therethrough, an output circuit for said device, a plurality of receiving elements and means for connecting said receiving elements in succession in said output circuit. 0

33. In a signaling system, an electric discharge device, means for applying telegraph code signal impulses to said device to produce a discharge therethrough, the magnitude of which is independent of the amplitude of the impressed signals, an output circuit for said device, a plurality of receiving elements and means for connecting said receiving elements in succession in said output circuit.

34. In a signaling system, an electric discharge device, means for applying telegraph code signal impulses to said device to produce a discharge therethrough, an output circuit for said device, a plurality of receiving elements and a distributor in said output circuit for determining the period of operation of said device in response to each signal impulse applied thereto and for connecting said receiving elements in succession in said output circuit.

35. In a signal system, apparatus for increasing the effective length of signal impulses comprising an electric discharge device responsive to signal impulses, said device being characterized by continued operation unaffected by signal impulses after being started by a signal impulse applied thereto, an output circuit for said device and a distributor in said output circuit.

36. In a signaling system,'an electric discharge device, means for applying telegraph code signal impulses to said device to produce a discharge therethrough, an output circuit for said device, a telegraph recorder having a plurality of selecting magnets and a distributor in said output circuit connecting said magnets in succession in said output circuit in synchronism with said signals.

37. In a telegraph receivin system, a source of signals, means for lling in the attenuated impulses comprising'two electric discharge devices, means for a plying received signal impulses to said evice alternately, means for creating a discharge through one of said devices in response to signals of one polarity and means for blocking a discharge through the other tube when the following signal is attenuated to a predetermined degree.

38. In a telegraph receiving system, a source of signals, means for filling in the attenuated impulses comprising two electric discharge devices, means for applying received signal impulses to said device alternately and means for periodically creating and interrupting the discharge throu h one of said devices and continuously bloc ing the discharge through the other device when said signals are attenuated to a predetermined degree.

39. In a telegraph system, the combination of two electric discharge devices having input and output circuit, means for applying received signal impulses to said devices alternately, means normally restricting the discharge through said devices, means for applying a starting condition to one of said devices when a signal attenuated to a predetermined degree is applied thereto, an output circuit for each device and means in the output circuit of an operating tube responsive to current flow therein for preventing a discharge in the other tubes when the following signal applied thereto is attenuated to a predetermined degree.

40. In a telegraph system, the combination of two electrostatically controlled gas discharge tubes having input and output circuits, means in the input circuit for ap plying received signal impulses to said tube alternately, means for applying a bias in said input circuit of a nature to prevent a discharge through said tubes, a source of potential adapted to be connected in said input circuit simultaneously with the application of received signal impulses to said tubes, said potential being in opposition to said bias and serving to apply a starting potential to the tube to which it is connected when the signal impulse is of an indeterminate polarity, said input and output circuits having a common path and means in said path operating when there is a current flow in the input circuit of one tube for preventing the starting of a dis charge through another tube, when the signal applied to the last mentioned tube is of an indeterminate polarity.

41. In a telegraph system, the combination of two electrostatically controlled gas discharge tubes having input and output circuits, means in the input circuit for a plying received signal impulses to said tu e alternately, means for applying a bias in said input circuit of a nature to prevent a discharge through said tubes, a source of potential adapted to be connected in said input circuit simultaneously with the application of received signal impulses to said tubes, said potential being in opposition to said bias and serving to apply a starting potential to the tube to which it is connected when the signal impulse is of an indeterminate polarity, said input and output circuits having a common path and a resistance in said path arranged so that the potential drop thereacross, when there is a current flow in the output circuit of one tube, will apply a blocking potential to the input of the other tube, of such value as to prevent the starting of a discharge therethrough when the signal applied thereto is of an indeterminate polarity.

42. In a telegraph system, a source of code signal impulses of varying polarity, a pair of electric discharge devices having controlling and controlled circuits, means in said controlling circuit for applying said signal impulses alternately to said devices to create a discharge therethrough and current responsive means in said controlled circuit.

43. In a telegraph system, a source of re current signal impulses, a pair of electric discharge devices having controlling and controlled circuits, means in said controlling circuit for applying said signal impulses alternately to said devices to create discharges therethrough, means for maintaining the discharge through each device independently of the signal and means for terminating the discharge through one device after the application of the succeeding signal to the other device.

44. In a telegraph system, a source of recurrent signal impulses, a plurality of electric discharge devices of the type in which a discharge once started therein continues independently of the starting condition, means for applying starting or non-starting conditions to said tubes in succession in accordance with the received marking or spacing signal impulses, respectively, and means for interrupting the discharge through each tube before the reapplication of a starting condition thereto.

45. In a telegraph system, a source of recurrent signal impulses, a plurality of electric discharge devices of the type in which discharge once started therein continues in dependently of the starting condition, means for applying starting or non-starting condi tions to said tubes in succession in accordance with the received marking or spacing signal impulses, respectively, and means for interrupting the discharge through each tube after the arrival of the succeeding signal impulse but before the arrival of the impulse which controls the application of a starting or non-starting condition thereto.

46. In a telegraph system, means for increasing the effective length of signal impulses comprising a pair of electrostatically controlled gas discharge devices, means for distributing received signal impulses to said devices alternately to create discharges therethrough, means for maintaining the discharge through each tube for a period longer than the normal period of the received impulses and means for interrupting the discharge therethrough before the application of a succeeding impulse thereto.

47. In a telegraph system, a source of signals, a resistance element, means for causing a current flow through said resistance in accordance with a received signal impulse, an electric discharge device and means responsive to the drop in potential across said resistance for controlling the operation of said device.

48. In a telegraph system, a source of signals, a resistance element, means for causing a current flow through said resistance element in accordance with a received signal condition, a gaseous conduction device having a starting means, said starting means being connected to said resistance whereby the drop in potential across said resistance due to current flow therethrough, restricts the starting of said device and means for applying a potential to said starting means in accordance with another signal condition to overcome said restriction whereby to create a discharge through the device.

49. In a telegraph system, a source of signals, a plurality of electric discharge devices, means for normally applying starting conditions to said devices in succession, when no signals are received from said source and means responsive to the creation of a discharge through one device for precluding the starting of a discharge through the other thereof.

50. In a telegraph system, a source of signals, an electric discharge device and means operating in substantial synchronism with said signals for intermittently applying a starting condition to the device when no signals are received.

51. In a telegraph system, a source of signals, an electric discharge device and means operating in substantial synchronism with said signals for intermittently applying a starting condition to the device when no signals or signals of a marking character are received and means for applying a nonstarting condition to the device when a signal of spacing character is received.

52. In a telegraph system, a source of telegraph signals, an electric discharge device and means for creating an intermittent discharge through said device in timed relation to every alternate signal impulse when the amplitude of said signal impulses is below a predetermined minimum.

53. In a telegraph system, means for increasing the effective length of signals comprising a plurality of electric discharge devices, means for distributing said signals in succession to said devices to create dis charges therethrough, means for maintaining said discharges independent of the continued application of signals to said devices, an output circuit for each device and contact means in each output circuit for determining the period of operation of the device associated therewith, said contact means being arranged to continue the operation of one device into the period of operation of the succeeding device.

54. In a duplex telegraph system, a main line, an artificial line, a receiving net work connected between said main and artificial lines including a resistance element, an electric discharge device having input circuit connected across said resistance whereby discharges are produced therein due to the drop in potential across said resistance occasioned by the incoming signals.

55. In a duplex telegraph system, a main line, an artificial line, a receiving net work connected between said main and artificial lines including a resistance element, an electric discharge device having input circuit and means for connecting said input circuit across said resistance in synchronism with the received signals whereby discharges are produced in the device due to the potential drop across said resistance occasioned by the incoming signals.

56. In a duplex system, amain line, an artificial line, a current conducting path for received signals between said main and artificial lines, an electric discharge device, means for starting a discharge through said device upon predetermined current flow through said path, produced by said signals, means for maintaining said discharge independent of current flow and means for terminating the discharge in definite time relation to said received signals.

57. In a duplex telegraph system, a main line, an artificial line, an electrostatically controlled gas discharge path, a controlling circuit therefor connected between said main and artificial lines and arranged for producing a discharge throu h said path, upon reception of predetermined signals and means independent of said signals for 1nterrupting the discharge.

58. A duplex telegraph system, comprising a main line, an artificial line, a transformer having its primary winding connected across said main and artificial lines and an electric discharge tube havingan iir put circuit including the secondary wind ng of said transformer, said device responding to direct current telegraph signals transmitted over said line and impressed on the primary of said transformenand serving to repeat the same of substantially full duration and uniform magnitude.

59. A duplex telegraph system, comprising a main line, an artificial lrne, a transformer having its primary Winding connected across said main and artificial lines. an electric discharge tube having an input circuit including the secondary winding of said transformer and means for connecting the secondary winding of said transformer in said input circuit during the forward part only of each signal impulse.

60. In a telegraph system, a source of signals, a transformer, an electric discharge tube havin an input circuit and means for applying t e rising portion only of each signal impulse to said input circuit through said transformer, to create a discharge through the tube.

61. In a telegraph system, a source of signals, a transformer, an electric discharge tube having an input circuit and contact mechanism for connecting the primary winding of the transformer to said signal source and the secondary winding in said input circuit in substantial synchronism with the signals.

62. In a telegraph s stem, a source of signal impulses, a trans ormer, signal responsive means in the secondary circuit of said transformer and means for connecting the primary winding of the transformer to said source of signals in substantial synchronism therewith.

63. In a telegraph s stem, a source of signal impulses, a trans ormer, signal responsive means in the secondary circuit of said transformer and means for connecting the primary winding of the transformer to said source of signals during the period of increase of each signal impulse and for dlSCOlb necting said winding from the source of signals during the period of decay of the impulse.

64. In a telegraph system, a source of 51gnals, an electric discharge device, a non-conductive coupling between said source of signals and said device whereby the device is caused to respond to received signal 1mpulses to produce a discharge thcrethrough and means independent of said signals for interrupting the discharge.

65. A regenerative repeater comprising an electrical discharge device, an output circuit therefor, a plurality of storage elements, means for creating discharges through said device in accordance with received signals and means for connecting said storage elements in succession in said output circuit in synchronism with said received signals.

66. A regenerative repeater comprising an electric discharge device, an output circuit therefor, a plurality of storage elements, means for creating discharges through said device in accordance with receivedsignals, means for connecting said storage elements in succession in said output circuit in synchronism with said received signals, an outgoing line and a transmitter associated with said storage elements for repeating the reeeived signals to said outgoing line.

67. A regenerative repeater comprising an electric discharge device, an output circuit therefor, a plurality of storage elements, means for creating discharges through said device in accordance with received signals, means for connecting said storage elements in succession in said output circuit in synchronism with said received signals, an outgoing line, one of said storage elements serving to repeat a received signal impulse over the outgoing line during the time of connection of the succeeding storage element in the output circuit.

68. A regenerative repeater comprising an electrostatically controlled arc discharge tube, input and output circuits therefor, a

source of signals, means for connecting said source of signals in the input circuits in synchronism with the signals to start discharges through said tube, means independent of the signals for interrupting said discharges, a plurality of storage elements and means for connecting said storage elements in succession in the output circuit during such discharge periods.

69. A regenerative repeater for a telegraph system comprising an electrostatically controlled arc discharge tube, means for applying received signals of attenuated or distorted form to said tube to initiate a discharge therein, the magnitude of which is constant and independent of the amplitude of the received signals, means for prolonging said discharge for a full signal period and means for utilizing said discharge for re-transmitting the signals in regenerated form.

70. A telegraph system comprising a source of signals, a circuit interrupting device operating in substantial synchronism with said signals, a corrector mechanism for said device, an electric discharge tube responsive to received signal impulses, and a second electric discharge tube, normally nonresponsive to signal impulses, but responding to said signals when an out of phase condition of said device occurs, said second discharge device, upon operation thereof, actuating said corrector mechanism to restore the phase relation of said device, relative to the signals.

71. A telegraph system comprising a source of signals, two electric discharge tubes, means for distributing a different part of each signal impulse to each of said tubes, an output circuit for each tube, a signal receiving device in the output circuit of one tube and a control mechanism in the output circuit of the other tube.

72. A telegraph system comprising a source of signal impulses, a plurality of electric discharge tubes, and means for distributing a single signal impulse to said tubes in succession to initiate discharges therein, said discharges being maintained independently of the continued application of the signal impulse to said devices.

73. A telegraph system comprising a source of signals, two electric discharge tubes, a distributor operable in synchronism with said signals, for distributing different parts of each signal impulse to each of said tubes, an output circuit for each of said tubes, a signal receiving device in the output of one of said tubes and a control mechanism for said distributor in the output circuit of the other tube.

74. A signal squaring and lengthening device comprising an electric discharge tube of the type in which the discharge may be started by momentary "application of a signal condition thereto and continued at a uniform magnitude independently of signal conditions, and a timing device for interruptin the discharge.

75. I n a communication system, a source of signals, a plurality of electric discharge tubes having input and output circuits, means for selectively connecting the in at circuit to said source of signals to create 'scharges in said tubes selectively, and means in the output circuit of said tubes for interrupting the discharges therethrough.

In testimony whereof I affix my signature.

HAKON H. HAGLUN D.

DISCLAIMER 1,901,296.-Hak0n H. Hhalglund, Flushing, N. Y. MULTIPLEX TELEGRAPH SYSTEM. Patent dated arch 14, 1933. Disclaimer filed June 1, 1935, by the patentee, the asslgnee, The I Vestem Union Telegraph Company, assenting.

Hereby disclaims the system defined in claim 47 of said patent, No. 1,901,296, except when llmlted to read upon the disclosure of said patent and wherein said resistance element is arranged to be connected in both the input and output circuits of the electric dlscharge device.

{Oficial Gazette June 18. 1935.] 

